1. Field of the Invention
The present invention relates to a both-side printing device which adjusts the mutual position of patterns to a predetermined relation and prints the patterns on both sides of a both-side sensitive body of a predetermined thickness, in which the relation of the mutual position of individual patterns to be formed on the both-side sensitive body can be detected prior to the both-side printing.
2. Description of the Prior Art
In a both-side printing device which adjusts the relation among mutual positions of individual patterns and prints the patterns on both-sides of a both-side sensitive body, it is necessary to observe or detect the relation of mutual positions of patterns to be formed on both sides of a sensitive body prior to the printing.
Various methods have been proposed for observing the positional relation, but none of these methods have been successful.
Descriptions will be made hereinunder on one of the typical prior arts.
Prior to the printing, a non-transparent sheet, instead of a sensitive body, having the same thickness as the sensitive body is arranged at the position on which the sensitive body is to be put, and a microscope objective lens for observing both patterns to be formed on the both sides of the non-transparent sheet is arranged. However, this method has a defect that proper correspondence of the non-transparent sheet to the view fields is very hard to obtain.
According to another conventional method, patterns are formed by the light transmitted through a sensitive material and the pattern on one side is compared with the pattern on the other side. This method has a defect that proper comparison of the patterns can not be obtained.